Ukraine is sending a top-level military delegation to Sochi, south Russia, to help investigate the mid-air explosion of a passenger jet that has been linked to a misfired Ukrainian missile, a senior Russian Security Council official said Sunday.

"A delegation from the Ukraine armed forces will be here tomorrow morning to help the expert investigation at the scene," said Vladimir Potapov, the Security Council's assistant secretary.

The six-strong delegation would be led by General Valery Kaminsky, the head of Ukraine's anti-air defense force, Potapov added.

A spokesman for the Ukrainian defense ministry told AFP that the delegation would provide "all the photographic, audio and radio information" it had relating to the relevant missile exercise in the Crimean peninsula.

"We will do everything possible to contribute to the work of the Russian experts," the spokesman added.

Some 20 experts from Israel arrived in this Black Sea city Sunday to help examine the wreckage of the Sibir airlines Tu-154 plane, most of whose passengers were Israeli citizens on Thursday's flight from Tel Aviv to Novosibirsk.

The Russian authorities at first favored a terrorist attack as the most likely cause of the explosion, less than a month after hijackers almost simultaneously crashed four planes in the United States, killing some 5,500 people.

But Russian Defense Minister Sergei Ivanov said on Saturday that neither he nor President Vladimir Putin were satisfied with Ukrainian reports that the land-to-air missile exercise had nothing to do with the blast.

Ivanov added that he had sent an "urgent message" to his Ukrainian counterpart Olexander Kuzmuk to provide information on a missile he says was fired four minutes before the plane crashed on Thursday.

US authorities have also said they believe a Ukrainian missile was involved -- SOCHI, Russia (AFP)